Impeller Assembly and Method of Using Same

ABSTRACT

An impeller assembly including a pair of plates with one of the plates having a plurality of blades and an interlock structure for aligning and coupling the plates together. A disclosed example of the interlock structure includes a plurality of latch members extending from one plate and locking into apertures of the other plate. The interlock structure may also include a plurality of channels engaging the blades. The blades of the impeller may engage a pair of latch members in a saddle manner. A method of using the impeller assembly within an air blower is also disclosed.

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. 119(e) from provisional U.S. Patent Application No. 60/893,349 filed Mar. 6, 2007 the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to impeller devices for moving fluids. More specifically, the invention relates to the assembly of impeller components.

BACKGROUND OF THE INVENTION

Impellers are a rotating component of a pump, fan, or other device that moves fluids. Impellers transfer energy from a prime mover to a fluid. A radial impeller forces the fluid generally outwards from the center of rotation. There are several types of impellers that are commonly found in various operations. One type of impeller uses one shroud which is a backplate mounted on the side of the blades opposite to the side of the impeller where the air enters. A second type uses two shrouds, a backplate and a cone that is mounted on the side of the blades where the air enters the impeller. A third type uses a single backplate in the center of the blades and two cones on the ends of the blades.

Impellers that have both a backplate and a wheel cone typically have blades between the plates. In many applications, the blades are formed integrally with one or both cover plates. Fluid to be pumped is introduced into the impeller housing at one side thereof. The shaft rotates so as to rotate the impeller thereby creating regions of high and low pressure within the impeller housing and impelling fluid through the assembly.

Both impellers with cones and without cones have advantages and disadvantages relative to each other. It is less expensive to manufacture impellers without cones but they require tighter assembly tolerances for fans with low specific speeds. Impellers with cones are significantly more expensive to manufacture as they require welding or other time intensive manufacturing processes to form them. Further, the welding or connection point of the cone to the impeller is often the weakest link of the impeller. However, they are usually more efficient than impellers without cones especially for impellers with low specific speeds.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to an apparatus and method for forming a closed faced impeller. In one example, a pair of plates is provided with one of the plates being adapted for coupling to a shaft means and the other plate having a concentric aperture adapted to pass a fluid there through. One of the pair of plates is provided with a plurality of blades for engaging a fluid. Preferably the blades are formed integrally with a plate. Alternatively, the blades may be formed on a separate backplate which is disposed between the upper and lower cover plates. The other pair of plates is provided with a plurality of blade interlocks adapted to couple the upper and lower cover plates together. In one embodiment, the interlocks are defined as resilient latches.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:

FIG. 1 is an isometric view of an impeller assembly according to one embodiment of the invention;

FIG. 2 is an isometric view of the backplate portion of the impeller assembly of FIG. 1;

FIG. 3 is an isometric view of the backplate portion of the impeller assembly of FIG. 1;

FIG. 4 is an isometric view of the cover plate portion of the impeller assembly of FIG. 1;

FIG. 5 represents an enlarged portion of FIG. 4 as indicated by circle, C5;

FIG. 6 represents an enlarged portion of FIG. 5 as indicated by circle, C6;

FIG. 7 is a cross sectional view of a portion of the impeller assembly of FIG. 1;

FIGS. 8 and 9 are a cross sectional views of the impeller assembly of FIG. 1;

FIG. 10 is a blower apparatus incorporating an impeller assembly of FIG. 1; and

FIG. 11 is the blower apparatus of FIG. 10 with a portion removed.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, FIG. 1 illustrates an impeller 100 according to one example of the present invention. Impeller 100 includes a lower backplate 10, an upper cover plate 12 and a plurality of blades 14 between the plates 10, 12. In the context of this specification, the terms “upper” and “lower” do not indicate a particular orientation of the components or assembly, or a particular relative position, but are employed for distinguishing purposes.

Referring to FIG. 2, blades 14 of backplate 10 may be formed integrally on an upper surface face of backplate 10. Backplate 10 may be of pressed metal construction or manufactured from a polymeric material. In the illustrated embodiment, at least a portion of the blades 14 are of sufficient height to extend between the backplate 10 and cover plate 12, and so form passageways between backplate 10 and cover plate 12. During impeller operation, fluid is moved from the center of the impeller to the outer edge of the impeller via the passageways. Blades 14 may be radially aligned (as shown in this example) or involute and serve to create regions of high and lower pressure within the impeller assembly during impeller operation, so as to impel fluid through the impeller assembly

Backplate 10 also includes a center hub 22 with blades 14 extending in a generally radial manner from center hub 22 to an outer edge 26 of backplate 10. Backplate 10 includes a center aperture 28 adapted to receive a drive shaft (not shown). Center aperture 28 may be splined or include other coupling structures useful to transfer torque from a drive shaft to impeller assembly 100. In another example of the invention, center hub 22 may be separated from blades 14.

In the illustrated embodiment, each blade 14 includes a generally flat ridge portion 30 and a downwardly tapering portion 32 which extends toward the outer edge 26 of backplate 10. Each blade 14 of backplate 10 also defines a pair of generally flat blade side surfaces 33, 34. Blade 14 also includes apertures 36, each defined near the base of blade 14. Apertures 36 are sized to receive portions of an interlock structure of cover plate 12 as described hereinafter.

FIG. 3 is an illustration of backplate 10 of FIG. 2 and illustrates the generally radial nature of aperture 36 locations relative to center aperture 28.

Referring to FIG. 4, cover plate 12 includes a central aperture 39 through which fluid passes during impeller operation. Cover plate 12 includes an interlock structure for coupling the backplate 10 to the cover plate 12. In this example, the interlock structure includes a plurality of torque transfer components 40 and a plurality of latch members 42. In the example of FIG. 4, torque transfer components 40 are radially aligned and spaced and sized to receive upper portions of blades 14 upon assembly. Channels 44 of torque transfer components 40 are shown as continuous channels, while in alternative embodiments, the channels 44 may be broken. The torque transfer components 40 are of sufficient integrity so as to transfer some of the torque applied to backplate 10 to cover plate 12 during impeller rotation. Another purpose of torque transfer components 40 is to align backplate 10 with cover plate 12 during assembly

FIG. 5 represents an enlarged view of FIG. 4 as represented by circle, C5, in FIG. 4. In this example, latch members 42 are shown as a pair of extending tines with detents 50 at uppermost portions of the tines. Latch members 42 are resilient and allow each tine to deflect away from each other during impeller assembly. Detents 50 are sized and shaped to cooperate with apertures 36 so as to lock the cover plate 12 to the backplate 10. As

FIG. 6 represents an enlarged view of FIG. 5 as represented by circle, C6, in FIG. 5. Pairs of tines of latch members 42 include opposed surfaces 52 at detents 50. Surfaces 52 of latch members 42 engage a portion of blade 14 within apertures 36, as shown by FIG. 7 which is a cross sectional view taken generally perpendicular to a base surface of impeller 100.

During assembly of impeller 100, backplate 10 and cover plate 12 are aligned and brought together so that tines of latch members 42 engage blades 14 and deflect away from blades 14 until detents 50 engage flat surfaces 59 of apertures 36, whereupon the times return to position. At the same time, channels 44 of the torque transfer components 40 engage the sides 33, 34 of blades 14 as the backplate and cover plate are brought together. As shown in FIG. 8, the resilient latch members 42 have snapped into the apertures 36 to hold the cover plate 12 and backplate 10 during rotation such that separation of the two components is minimized.

FIG. 8 also illustrates the relationship between a curved portion 80 of cover plate 12 and a correspondingly curved section within downwardly tapering portions 32 of back plate 10. As a consequence cover plate 12 engages back plate 10 throughout the tapering portion 32 of back plate 10.

FIG. 9 is another cross sectional view of the example of the invention showing the mating relationship between blades 14 of backplate 10 and channels 44 of cover plate 12.

FIG. 10 illustrates an example of a blower apparatus incorporating impeller 100. Housing 60 defines a aperture 61 into which impeller 100 is located. Housing 60 includes a fluid inlet 62 and a fluid outlet 63. Conduits of a fluid system (not shown) are in fluid communication with inlet 62 and outlet 63. FIG. 11 is a cross-sectional illustration of the blower apparatus of FIG. 10. A drive shaft is coupled to the impeller at hub 22. As the drive shaft is rotated, impeller 100 rotates within housing 60 drawing fluid from inlet 62 and through the impeller 100 prior to exit at outlet 63. Some amount of torque supplied by drive shaft at backplate 10 effectively is transferred via the blades 14 and torque transfer components 40.

In alternative examples of the invention, the torque transfer components and latch members may be combined. In another example, the torque transfer components may engage only a single side of the blades, instead of opposed sides of the blades as disclosed herein. Torque transfer components are preferably configured to engage one or more surfaces of the blades. Torque transfer components may assume different sizes or shapes, though a smaller profile is desirable to minimize disturbances to fluid flowing through the impeller.

In another example of the invention, latches extend from backplate 10 and engage apertures or cavities of cover plate 12. In another example, detent surfaces similar to surfaces 52 of the aforementioned example may engage a back surface of backplate 10 instead of blades 14. Other examples of the present invention may include fewer latch members than blades 14 or an even number of blades 14. In another example of the invention, the latch members would not make contact with the sides 33, 34 of blades 14, but instead be located between adjacent blade 14 pairs. In yet another example of the invention, the latch members may be outwardly inclined as opposed to inwardly inclined as in the example of FIG. 4. In another example, latch members may extend into generally perpendicular contact with the backplate relative, for example, to a back surface of the backplate 10. In another example of the invention, the latches 42 could be pinned in place, secured with threaded fastener(s), or coupled in other means.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. 

1. An impeller assembly comprising: a pair of generally circular plates; a plurality of blades between the plates; and interlock structure on at least one of the pair of plates, said interlock structure including at least a torque transfer component which engages sides of said plurality of blades.
 2. The impeller assembly of claim 1 with said interlock structure further comprising a plurality of latching members.
 3. The impeller assembly of claim 1 wherein the plurality of blades extend from a center hub on one of the pair of plates.
 4. The impeller assembly of claim 3 wherein the hub includes an aperture for receiving a drive shaft to rotate the impeller assembly during operation.
 5. The impeller assembly of claim 1 wherein the interlock structure is defined on one of the pair of plates and the plurality of blades are defined on the other plate.
 6. The impeller assembly of claim 1 wherein the interlock structure and the plurality of blades are defined on the same plate.
 7. The impeller assembly of claim 5 wherein the torque transfer components define a plurality of channels, with each channel being sized to engage side surfaces of one of the plurality of blades.
 8. The impeller assembly of claim 6 wherein the plurality of latching members include a plurality of tines each having a detent structure.
 9. The impeller assembly of claim 7 wherein one pair of the plurality of tines engage each blade of the impeller.
 10. The impeller assembly of claim 8 wherein the detent structures engage apertures formed upon side surfaces of the plurality of blades.
 11. The impeller assembly of claim 1 wherein the interlock structure and the plurality of blades are defined on the same plate.
 12. An impeller assembly comprising: a backplate having a plurality of blades defined upon a surface of the plate, said blades being configured to move a fluid during operation of the impeller assembly, and having a hub including a coupling component; a cover plate having a center aperture; a interlock structure, said interlock structure comprising a plurality of torque transfer components, with each of said plurality of torque transfer components extending away from one of said plates and engaging a surface of the other one of said plates; and a plurality of fluid passageways extending from the center aperture to outer edges of the impeller assembly, with each of said fluid passageway being defined between a pair of blades, a portion of the cover plate and a portion of the back plate.
 13. The impeller assembly of claim 12 wherein the interlock structure further comprises a plurality of latching members, with at least one of said plurality of latching members engaging one of the plurality of blades so as to lock the cover plate to the backplate.
 14. The impeller assembly of claim 13 wherein the latching members include a plurality of resilient tines with detent structures, and each detent structure engages a aperture of one of the plurality of blades.
 15. The impeller assembly of claim 14 wherein a pair of resilient tines engage opposed side surfaces of one of the plurality of blades.
 16. The impeller assembly of claim 15 wherein a pair of detent structures at ends of the pair of tines engage a pair of apertures on the opposed side surfaces.
 17. The impeller assembly of claim 12 wherein the torque transfer components each define a channel sized to engage one of the plurality of tines.
 18. The impeller assembly of claim 17 wherein the channel is sized to engage a ridge portion of said tine.
 19. The impeller assembly of claim 12 wherein the coupling component of the hub includes an aperture sized to receive a drive shaft.
 20. The impeller assembly of claim 12 wherein the interlock structure includes multiple latches extending from one of said plates and latching into the other one of said plates.
 21. The impeller assembly of claim 20 wherein said multiple latches extend from said cover plate and latch into blade apertures of said backplate.
 22. The impeller assembly of claim 20 wherein said multiple latches extend from said cover plate and at least partially pass through said backplate.
 23. The impeller assembly of claim 20 wherein the latches extend from the back plate and latch into the cover plate.
 24. The impeller assembly of claim 20 wherein the latches extend from the cover plate and latch into the back plate.
 25. A method of providing a fluid pump comprising: providing an impeller assembly according to claim 12; inserting the impeller assembly into a housing having a fluid inlet and fluid outlet; and coupling the impeller assembly to a drive shaft, with rotation of the driveshaft causing the impeller assembly to rotate within the housing causing a fluid to flow from the fluid outlet through the center aperture of the cover plate and through the plurality of fluid passageways prior to exiting the housing via the fluid outlet, with a torque supplied by drive shaft being transferred from the hub to the cover plate via the torque transfer components.
 26. The method of claim 25 further comprising: locking the cover plate to the backplate with a plurality of latches extending from the cover plate and engaging a plurality of apertures defined on side surfaces of the plurality of blades.
 27. The method of claim 25 wherein the plurality of apertures are defined near a base of the backplate and the plurality of latches are defined by a plurality of tines, with each tine having a detent structure engaging one of said plurality of apertures. 